Exhaust water separator for marine engines

ABSTRACT

A water separator for a marine propulsion system. Arcuate exhaust elbows are provided which force cooling water in the exhaust to the outside by centrifugal action. This water is removed and expelled through the transom.

United States Patent [1 1 North et al.

[ Sept. 18, 1973 EXHAUST WATER SEPARATOR FOR MARINE ENGINES [75]Inventors: Irving W. North, Oshkosh; Herbert A. Bankstahl, Fond du Lac,both of Wis.

[73] Assignee: Brunswick Corporation, Chicago, 111.

[22] Filed: Jan. 17, 1972 [21] Appl. No.: 218,315

[52] U.S. Cl 60/310, 60/311, 55/D1G. 30 [51] Int. Cl. F0ln 3/02 [58]Field of Search 60/310, 311;

[56] References Cited UNITED STATES PATENTS 2,763,982 9/1956 Dega 60/3103,263,413 8/1966 Vactor 60/310 3,495,385 2/1970 G1ass 60/310 3,541,78611/1970 Sarra 60/310 Primary Examiner-Douglas Hart Attorney-Roy T.Montgomery [57] ABSTRACT A water separator for a marine propulsionsystem. Arcuate exhaust elbows are provided which force cooling water inthe exhaust to the outside by centrifugal action. This water is removedand expelled through the transom.

10 Claims, 4 Drawing Figures Patented Sept. 18, 1973 4 7. I'll 1 wwmwwv/ Vlwllllljldw/lv V EXHAUST WATER SEPARATOR FOR MARINE ENGINESBACKGROUND OF THE INVENTION This invention relates to a cooling systemfor a marine propulsion system wherein cooling water is discharged intothe exhaust.

In constructions heretofore employed, cooling water has been forced tocompletely follow the path of the engine exhaust. In an effort to relivethe resultant back pressure on the engine, pressure relief holes havebeen provided to allow early escape of the water and exhaust mixture.

' It has been found that the flow characteristics of the exhaust mayvary between systems and at different speeds of a single system. As aresult, often primarily exhaust gases escape through the pressure reliefholes and effectiveness in relieving back pressure is reduced.

SUMMARY OF THE INVENTION The present invention provides means forremoving and expelling a substantial portion of the water from theexhaust system which is effective at any speed. There is provided anarcuate exhaust elbow which causes the water to be thrown to the outsideof the elbow by centrifugal force. A water separator is provided at theend of the arcuate elbow which removes and expels the water flowingalong the outside of the elbow. Thus, it is assured that the majority ofthe water is removed and not forced through the outboard drive unit.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing illustratesthe best mode presently contemplated for carrying out the invention.

In the drawing:

FIG. 1 is a perspective exploded view of the propulsion system of thisinvention with parts in section.

FIG. 2 is an enlarged elevation of the water separator.

FIG. 3 is a section view along lines 3-3 of FIG. 2.

FIG. 4 is an enlarged section view generally along lines 4-4 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,there is shown a marine internal combustion engine having exhaustmanifolds 11 and manifold elbows 12. The engine is carried in a boat,the transom of which is indicated by 14. An outboard drive unit 15 isalso carried by the boat transom l4 and is drivingly connected in aconventional manner to the engine 10. Two exhaust elbows 16 areprovided, each being attached to the respective manifold elbow 12. Theexhaust elbows 16 are arcuate in shape and are attached at one of theirends by a water separator 18. interposed between the end of each exhaustelbow l6 and the water separator 18 is a flapper valve 20 which servesto prevent back flow of water through the exhaust system.

The water separator 18 includesexhaust inlet passages 21, an exhaustoutlet passage 22, and water outlet passages 23. The rear face 34 of thewater separator 18 is connected in a conventional manner to the frontface 35 of the bottom portion of the gimbal housing 36 such that waterpassage 23 in the water separator 18 align with water passages 38 in thegimbal housing 36. Water passages 38 are in turn connected to a wateroutlet 39 which expels the water back into the lake.

Passage means for passing exhaust gases from the engine to an exhaustoutlet are provided which are formed through the elbows 16, valve 20,separator 18, bellows 26, drive unit 15, and propeller 28. The directionof travel of the exhaust is indicated by arrows 25. Exhaust flows fromthe'engine into the manifold 11, through the manifold elbows 12, theexhaust elbows 16, the flapper valves 20, the exhaust inlet passages 21,the exhaust outlet passage 22, the exhaust bellows 26, internal exhaustpassages (not shown), in the outboard drive unit 15, through thepropeller 28, and out the exhaust outlet 29 in the propeller 28.

Water is dumped from the engine block through hoses 30 into coolingpassages (not shown) in the exhaust manifolds. The cooling water is thenmixed with the exhaust at or near the outlet 32 of the manifold elbows12 in general accordance with the description in US. Pat. No. 3,541,786entitled Inboard Marine Engine Cooling System. The exhaust issufficiently cooled by the water to prevent damage to the flexiblematerial of the exhaust elbows 12, the flapper valve 20, the exhaustbellows 26, and the flexible hub of the propeller 28.

However, it has been found that forcing the water and exhaust gasmixture through the rather tortuous path of the exhaust bellows 26, theexhaust passages in the outboard drive unit 15, and the hub of thepropeller 28 creates undesirable back pressure on the exhaust of engine10. Thus, it is desirable to remove as much of the water as possibleprior to the bellows 26 and the outboard drive unit 15. It has beenfound that the mere provision of an exhaust relief outlet is notcompletely satisfactory to accomplish this purpose, since at some enginespeeds the water may flow through the exhaust passage means in an areaaway from the exahust relief. This-results in primarily exhaust escapingthrough the relif and is not as effective for relieving back pressure.

In the present invention there are provided arcuately formed exhaustelbows 16 which result in the water being forced by centrifugal actionto the outside wall of the elbows 16. The water which is forced to theoutside of the exhaust elbows 16 is collected at the bottom of the waterseparator 18 by the combined effects of centrifugal action and gravity.The water meets a raised wall portion 41 in the water separator 18 andis forced through water passage 23 into water passages 38 and expelledthrough water outlets 39.

The water separator 18 includes a pair of arcuate internal walls 43 toaid in turning the exahust at right angles and promote smooth flow ofthe exhaust gases.

It is apparent that many modifications and variations of the inventionas hereinbefore set forth may be made without departing from the scopeand spirit hereof.

What is claimed is:

I. In a marine device having a water cooled internal combustion engine,passage means for passing exhaust from the engine to an exhaust outlet,and means for injecting cooling water from the engine into the exhaustpassage means, the improvement comprising a water separator in thepassage means downstream from the injecting means and upstream from theexhaust outlet, said separator including a water passage means incommunication with the exhaust passage means in an area of primarilywater flow for separating and expelling a substantial portion of thewater from the passage means without substantially interfering withexhaust flow, said separator being operable without regard to enginespeed.

2. The improvement of claim 1, wherein said separator includes a raisedwall portion to aid in water separation.

3. The improvement of claim 1, including an arcuate member which formspart of the exhuast passage means such that the water is forced to theoutside of said member by centrifugal action, said member being upstreamfrom and connected to said water separator 4. The improvement of claim3, wherein said separator includes a raised wall portion to aid in waterseparation. a

5. The improvement of claim 3, wherein said arcuate member is generallyvertically disposed and connected to the engine at the top such thatwater is forced to the outside of said member by the additional affectsof gravity.

' 6. The improvement of claim 1, wherein said passage means are formedin part by an arcuate exhaust elbow connected at one end to said enginesuch that water is forced to the outside of said elbow by centrifugalaction and said separator is connected to the other end of said elbow,said water passage means being positioned to pick up and expel the waterflowing on the outside of said elbow.

7. The improvement of claim 6, wherein said separator includes a raisedwall portion to aid in water separation.

8. The improvement of claim 6, wherein said arcuate member is generallyvertically disposed and connected to the engine at the top such thatwater is forced to the outside of said member by the additional affectsof gravity.

9. The improvement of claim 3, wherein said arcuate member is generallyvertically disposed and connected to the engine at the top such thatwater is forced to the outside of said member by the additional affectsof gravity.

10. The improvement of claim 9, wherein said separator includes a raisedwall portion to aid in water separation.

1. In a marine device having a water cooled internal combustion engine,passage means for passing exhaust from the engine to an exhaust outlet,and means for injecting cooling water from the engine into the exhaustpassage means, the improvement comprising a water separator in thepassage means downstream from the injecting means and upstream from theexhaust outlet, said separator including a water passage means incommunication with the exhaust passage means in an area of primarilywater flow for separating and expelling a substantial portion of thewater from the passage means without substantially interfering withexhaust flow, said separator being operable without regard to enginespeed.
 2. The improvement of claim 1, wherein said separator includes araised wall portion to aid in water separation.
 3. The improvement ofclaim 1, including an arcuate member which forms part of the exhuastpassage means such that the water is forced to the outside of saidmember by centrifugal action, said member being upstream from andconnected to said water separator.
 4. The improvement of claim 3,wherein said separator includes a raised wall portion to aid in waterseparation.
 5. The improvement of claim 3, wherein said arcuate memberis generally vertically disposed and connected to the engine at the topsuch that water is forced to the outside of saiD member by theadditional affects of gravity.
 6. The improvement of claim 1, whereinsaid passage means are formed in part by an arcuate exhaust elbowconnected at one end to said engine such that water is forced to theoutside of said elbow by centrifugal action and said separator isconnected to the other end of said elbow, said water passage means beingpositioned to pick up and expel the water flowing on the outside of saidelbow.
 7. The improvement of claim 6, wherein said separator includes araised wall portion to aid in water separation.
 8. The improvement ofclaim 6, wherein said arcuate member is generally vertically disposedand connected to the engine at the top such that water is forced to theoutside of said member by the additional affects of gravity.
 9. Theimprovement of claim 3, wherein said arcuate member is generallyvertically disposed and connected to the engine at the top such thatwater is forced to the outside of said member by the additional affectsof gravity.
 10. The improvement of claim 9, wherein said separatorincludes a raised wall portion to aid in water separation.